The present invention relates generally to yardage systems and more particularly to a new and improved golf course yardage and information system.
Before starting play on an unfamiliar or infrequently played course, golfers typically familiarize themselves with the layout of each hole. This gives the golfer the knowledge at the tee box of a particular hole being played, for example, as to whether the hole is a xe2x80x98dog leg leftxe2x80x99, a xe2x80x98dog leg rightxe2x80x99, or straight; whether any hazards, such as sand traps, bunkers, and water traps, are hidden from view; whether and where the range is posted to calculate yardage from the ball""s (and the golfer""s) present location to the front of the green, the rear of the green, the pin, a key hazard, or a desired lay up position for the green approach shot.
Customarily, golf courses market informative books on the course in the pro shop, to indicate layout features for each hole and yardage from a few locations along the hole to the center of the green. Also, yardage markers typically are provided on sprinkler heads along the route of each hole, so that the player will know the range from that point to the center of the green. These playing aids provide information on the hole layout and location of hazards, and also allow the golfer, by pacing off yardage from the ball to the nearest sprinkler head, to estimate yardage from the ball to the center of the green. Such measures are by no means precise, but do enhance one""s knowledge of the hole, and thereby, an opportunity to improve one""s game. They also exact a costxe2x80x94slowing the pace of play of every golfer behind the one or more who are familiarizing themselves with the course, pacing off yardage, and so forth. Slow play has an adverse effect on the course""s daily revenue, as well as on other players"" enjoyment of the game.
Various proposals have been made toward improving golf course information systems. The intent of these ostensible improvements has been to reduce the average player""s score; to increase enthusiasm and speed of play; and to enhance the player""s knowledge of the course regarding every hole, the yardage from the ball or xe2x80x9cliexe2x80x9d to the green, the distance and bearing to the pin, and the location of hazards. Proposals have included use of buried electrical wires in various layout configurations about the course for interaction with mobile overland components such the golf information system disclosed in U.S. Pat. No. 5,044,634 to Dudley. Other proposals utilize radio direction finding or triangulation techniques, to inform the golfer of gross features of the course and distances from specific markers to the pin or flag for the hole being played such as those described in U.S. Pat. No. 4,703,444 to Storms, Jr. and U.S. Pat. No. 5,056,106 to Wang.
U.S. Pat. No. 5,364,093 to Huston (xe2x80x9cHustonxe2x80x9d) discloses a position and distance measuring system for a golf course that uses the capabilities of the existing U.S. government-sponsored Global Positioning System (GPS) which was established over the last 20 years with space satellites and ground based stations. The GPS system was established as a means for determining distance, range, and position for various governmental purposes, but has become quite useful in many industrial and commercial applications as well. A number of earth-orbiting satellites provide reference points from which to determine the position of a point on or near the earth, using the ground-based receivers. The orbits of these satellites are monitored by the ground station GPS receivers, and the travel times of signals received from the satellites are used to measure distance to each satellite. Each signal from a satellite is coded to permit the receiver to determine the elapsed time between transmission of the signal from the respective satellite and reception at the GPS receiver antenna, and thereby to calculate the distance as the product of that elapsed time and the speed of light. Receivers need not be restricted to large ground stations, but are available in portable, mobile and hand-held versions, for a multitude of private navigation, position and distance-measuring systems.
Distance measurements to three GPS satellites can accurately define the position of an object (i.e., that of the GPS receiver, whether of the stationary or portable type) on or near the surface of the earth. A fourth satellite provides a distance measurement that serves to verify clock timing within the GPS system. With several satellites in xe2x80x9cviewxe2x80x9d, and through the use of a computer, the GPS receiver theoretically can calculate distances virtually instantaneously with great accuracy. In practice, however, even small errors that typically occur in the calculated measurement of satellite signal travel time from system and natural phenomena severely reduce the accuracy of the distance and position calculations. Error causing phenomena include atmospheric propagation, receiver contributions, satellite ephemeris, and satellite clock. Furthermore, the U.S. Department of Defense (DOD) purposely introduces errors in the satellite signals to deny civilian users full accuracy. The combined effect of these errors can be as high as 100 meters or so. Erroneous measurements of this magnitude may be tolerated in many GPS-based measurement systems, but would be unacceptable in a golf course positioning and distance measuring system.
Huston proposed a golf course GPS system which employs purely conventional differential GPS, which has found wide use to reduce errors in distance measuring systems. The differential GPS (DGPS) system broadcasts error correction information from a ground receiver of known location in the vicinity of the user. Two GPS receivers are used, one at a known fixed position, so that the difference between that known position and its position calculated from the satellite GPS signal fixes the error in the signal. The fixed position (reference) receiver provides a continuous correction for use by all other receivers, which may be mobile, within its reception area. Knowledge of the error allows all distance and position calculations at the user""s receiver to be corrected. Conventional DGPS can reduce errors in position calculations to allow accuracies of within about five metersxe2x80x94quite suitable for most commercial needs, but still unacceptable for a golf course distance measuring system. However, the same conventional DGPS system may be used to determine the location of a golf cart receiver relative to the pin on a hole of a golf course as to determine the location of a ship relative to a land-based point of interest. Weather conditions and terrain have little effect on position determination in the GPS system, and few restrictions are imposed on size or location of a user""s receiver.
Details of DGPS are readily available from a number of sources, an example being Blackwell, xe2x80x9cOverview of Differential GPS Methodsxe2x80x9d, Global Positioning System, vol. 3, pp. 89-100, The Institute of Navigation, Washington, D.C. (1986). The Blackwell (Stanford Research Institute International) paper details four differential GPS techniques, one of which is virtually identical to the previously proposed GPS-based golf course positioning system.
It is a principal object of the present invention to provide a new and improved golf course yardage and information system utilizing DGPS.
Another object of the present invention is to provide such a system having considerably greater accuracy and reliability than is available with conventional DGPS by utilizing unique filtering algorithms.
Another object of the present invention is to provide such a system having a communications network between a base station and golf carts that efficiently utilizes its allocated bandwidth for data transmission while being relatively inexpensive thereby achieving low cost for the overall system.
Another object of the present invention is to provide such a system with a variable length communication network for such a system for easily and efficiently adding or removing golf carts from the network.
Another object of the present invention is to provide such a system with the capability of creating, storing and displaying high resolution color graphics such as a layout of all or a selected group of holes of the course on the base station monitor, and a layout of the current hole and color advertisements on the monitors in each of the golf carts.
Another object of the present invention is to provide an improved technique and method of surveying the layout of the golf course and collecting data therefrom for post-processing and storing of such data for later retrieval and display.
Another object of the present invention is to provide such a system having the capability of detecting when the golf carts are within predetermined zones or regions of the golf course for use in unique system features such as automatic display of the current hole on the monitor of each golf cart, measuring the pace of play for each hole, and automatic pop-up advertisements on the monitor of each golf cart as the carts transition from one hole to the next.
Another object of the present invention is to provide an improved technique and method for mounting a monitor to the roof of a golf cart for exceptional color readability in sunlight.
Before summarizing the best mode presently contemplated for practicing the golf course yardage and information system of the invention, it bears emphasis that the present invention is not limited to providing distances and information in the context of golf courses. Rather, it may be extended to any number of other consumer, commercial, and industrial applications of satellite navigation and digital communications technology. The present invention will be described in the context of a golf yardage and information system, embodied in what is referred to herein as the PROLINK1 yardage and course management system (or more briefly, as the xe2x80x9cPROLINK systemxe2x80x9d), but the invention is not limited to use on or for a golf course.
1PROLINK is a federally registered trademark of Leading Edge Technologies, Inc. of Chandler, Ariz., the assignee of the invention disclosed in this patent specification. 
The PROLINK system includes a golf cart-based subsystem, although it may be packaged alternatively or additionally into a hand-held unit carried by the golfer. Both such versions are included within the generic terminology of a mobile unit, a portable unit, or a roving unit. Each roving unit utilizes state-of-the-art DGPS technology, with considerable enhancement by the features and aspects of the present invention, incorporated in hardware and software.
The PROLINK system possesses the capability to create, store, and display a color or black and white graphical representation or map of the golf course on a video monitor in the cart (or on a liquid crystal display (xe2x80x9cLCDxe2x80x9d) of a hand-held unit). Each hole of the course is selectively displayed with all of its hazards and features, with the golfer""s fixed or changing position (strictly speaking, the cart""s position) superimposed thereon in real time during play of the hole. The system provides the golfer with an accurate measurement of the distance (typically, in yards) from the current tee box to the current pin placement (both of which may be subject to daily change by the course administrator), as well as from any other location of the cart on a hole to the pin or any other feature of the hole. In essence, an xe2x80x9celectronic yardage and hole feature bookxe2x80x9d is presented by which to enhance club selection for each lie of the ball during play.
An ancillary feature of the PROLINK system is its capability to display personal messages to a golfer at a selected cart, as well as to provide informative tips (xe2x80x9cpro tipsxe2x80x9d) at specific holes, and system-wide advertising and promotional messages. The PROLINK system includes a course management subsystem that enables the course administrator (typically the golf professional who operates the pro shop) to track the location of and to communicate selectively with each golfer or all golfers on the course, to monitor and improve the pace of play, and to compile a statistical data base on course operations. Personal messages may be sent to the selected carts and emergency or other overall messages may be sent system-wide at any time, while xe2x80x9cpro tipxe2x80x9d, advertising or promotional messages may be activated based on the cart""s location on the course, such as the time between exiting the green of a hole to entering the tee box of the next hole.
The cart-based or other type of roving unit of the PROLINK system provides advantages to the golfer without burdening or significantly changing the way the course or any particular hole is played, or how business is conducted by course management. Such advantages include (1) real-time, accurate indications of distance (typically within two meters) from the cart to significant course featuresxe2x80x94green, pin, hazards in fairway, etc., (2) a large (e.g., 7.5-inch), high resolution, color display of a map of entire course, individual hole, or green or other detailed features, on the cart monitor, and (3) the capability of individualized communications and messaging to and from the cart.
The position of the cart is displayed in real time on the map of the hole being played, both on the individual cart monitor and a monitor at the course management station. As the cart moves, the yardage-to-pin and yardage to hazard calculations are automatically updated on the display. According to a related feature of the invention, a separate movable cursor on the display allows the playerxe2x80x94by simply appropriately positioning the cursorxe2x80x94to obtain a precise yardage measurement to any feature shown on the hole map. Another feature is the capability to read the shot distance of each shot by simply pressing a xe2x80x9cshot distancexe2x80x9d button adjacent the display.
The golfer may selectively view the entire course layout or obtain a display of an individual hole, in full color, before, during, or after play. An automatic zoom feature increases the selected target area resolution, such as to view the contour of the green or the details of a particular hazard. If desired, the roving unit can record an entire gamexe2x80x94stroke-by-strokexe2x80x94to allow it to be replayed at home or elsewhere from a computer disk as it was originally displayed on the cart monitor. Alternatively, a xe2x80x9chard copyxe2x80x9d printout of each shot, from tee to fairway to green, may be obtained from a club house computer. The player can thus analyze the game, and devote time to problem areas to improve skills before the next round of play.
The most significant decision on each shot is selection of the golf club to play the lie relative to the pin location, hazards, and so forth. The PROLINK system enables the player to make consistently better and faster club selection. At the same time, the system enables the golfer to correct natural inconsistencies in swing that may otherwise be attributable to inadequate information concerning target distance and course layout.
In operation of the system, the hole display and yardage functions in the cart system are activated automatically at the beginning of each hole. Yardage from the roving unit to the pin and to key hazards such as traps and water are displayed and updated at all times on the display as these features are viewed. Four arrow keys allow the player to move a cursor around the hole display and obtain yardage to any point on the course. A single button press may, for example, provide a pro tip created by the course golf professional, or a blow-up of the green complete with contour lines for the critical approach shot. In addition, the player""s driving distance is displayed automatically after a tee shot, and the distance to the pin for the next shot is available automatically. After the player reaches the green, a screen allows advertising, promotional messages, and any other information, such as course trivia, to be displayed. When the player approaches within a fixed distance of, or reaches the next tee, the PROLINK system automatically moves to the next hole layout display for continuing play. Furthermore, the PROLINK system is non-intrusive in that a user could play an entire round of golf without pressing a single button and still obtain precise yardage to the daily pin placement and key hazards. Rather, the user is only required to interact with the system for advanced features such as pro-tips, enhanced green views or shot distance to name a few.
The course management portion of the PROLINK system includes a base station computer unit, receiver/transmitter unit and video monitor in the clubhouse (or other desired location) to give the course administrator better insight into daily operations and revenues. Principal advantages of the course management portion include (1) the capability to identify, locate and monitor movement of every golf cart on the course in real-time, with precise positioning during play on each hole, (2) use of that knowledge to pinpoint location and analyze cause of bottlenecks, toward improving speed of play, and greater enjoyment by all players, (3) compilation of an extensive computerized data base to provide management and designated staff personnel with accurate statistical insight into course operations and techniques for instituting improvements, and (4) availability of a convenient source of communication and messaging to all roving units, with potential concomitant revenue enhancement through advertising and promotions.
The data compiled as part of the club""s data base is readily used for management information system (xe2x80x9cMISxe2x80x9d) reporting to management and board members, and to provide reports complete with tables, charts and graphs on an as-needed basis for club members and players, or, in the case of municipal and other public courses, to provide necessary reports to the appropriate authorities as well as statistical and course information to players. The compiled data may include date and times rounds were commenced, player names for each round, tee times, actual start times, actual finish times, time required for each round, time required for each hole, strokes per hole, daily pin placements, and total rounds, by way of example.
The size of a golf course""s ranger staff may be reduced by virtue of having a wealth of information available to the course administrator from the PROLINK system. Despite their fewer number, the rangers may be used more efficiently by dispatching them to precise locations where bottlenecks or other barriers to efficient play are occurring. Each roving unit is assigned a unique ID number which is transmitted by the system for periodically monitoring (and displaying) (e.g., every 2 to 16 seconds, depending upon the number of carts on the course) each unit during play, for identifying selected golfers for messages, or those who may be causing problems, or for other purposes.
In particular, the PROLINK course management system includes a Course Management Computer (CMC), with a combination of radio frequency (RF) data links and personal computer (PC) modem links that allow the base station and golf carts to communicate and share information with one another. The network communication system of the PROLINK system employs a cost-effective and bandwidth efficient technique for the transmission of data between the base station and the golf carts. Frequency shift keying (FSK) is the modulation technique chosen for data transmission because FSK is both inexpensive and simple to implement thereby minimizing cost of the overall PROLINK system. Although FSK lacks bandwidth efficiency relative to other, more costly, modulation techniques, such as phase shift keying (PSK), the PROLINK system makes very efficient use of available bandwidth by employing a precise, time controlled time division multiplexed (TDM) scheme that is synchronized to a precise pulse per second (PPS) signal available from a GPS receiver for allocating to each cart and the base station a precise time to transmit its respective data. This ensures that when one cart is transmitting, all other carts as well as the base station are not transmitting. Such a precise, time controlled TDM communication network obviates the need for the base station to poll each of the carts to request it to send information and, thus, substantially increases the bandwidth efficiency of the communication network.
The PROLINK system also employs a unique technique and method for collecting data indicative of the layout of the golf course including such features as tee boxes, greens, fairways, water hazards and sand traps. Such collected data is then post-processed and efficiently stored in memory in vector form for later retrieval and display. Moreover, once the data representing the golf course is stored in memory, such data can be used to efficiently determine the location of a golf cart relative to predetermined zones or regions. To that end, the PROLINK system utilizes a unique zone detection algorithm and creates a number of different zones corresponding to actual areas or objects on the golf course. For example, zones are created corresponding to a tee box area or a green area of a particular hole on the course. Accordingly, the PROLINK system has the capability to detect a golf cart to be within an actual area on the golf course when the coordinates of the golf cart lie within the corresponding zone.
By the use of such a zone detection algorithm, various features of the PROLINK system are readily implemented. Such features include automatic hole display on the cart monitor as the cart enters the tee box zone of a new hole, and automatic pop-up, high resolution, color advertisements when the cart is in transition from one hole to the next. Additionally, the speed of play for a hole may be obtained by measuring the time from when a golf cart enters the tee box zone of a hole to when the cart exits the green zone of that hole.
Although use in connection with golf course operations is of principal interest, the PROLINK system architecture can be utilized for mapping and location information as well as command and control capabilities for mass transit, forestry, express package services, shipping, and other applications.